Chinese, English and Spanish are languages. Each has words and a grammar. Deaf people communicate with sign language. Sailors use flags. Dogs bark. If architecture is to be classed as a language, we have every right to ask what is being said and who is being addressed. The dictionary definitions are as follows:

Charles Jencks, in The Language of Post-Modern Architecture, suggests that architecture is a language that depends on double-coding (Jencks, 1991). It speaks to fellow architects and to the general public. An oversized door, for example, informs the public of a "main entrance to an important building'. At the same time, a second code can speak to fellow-architects who have moved beyond functionalism and can enjoy quotations, references, literary allusions, witticisms and arcane meanings. A classical portico on a new office block, for example, might say "I admire the geometrical purity of the classical tradition but believe it needs re-interpretation for our own time'. The second code, which is the subject of Jencks' book, operates through architectural styles. Unsuspecting readers might be surprised by this fact, as they would be if they opened a book on The Language of Electrical Engineering and found a discussion on the aesthetics of printed circuit boards. In his later writings Jencks talks of multiple-coding instead of double-coding.